Planar Macromolecular Semiconductors Enable Fast Electron‐Ion Transport Kinetics for High‐Performance Zinc‐Organic Batteries

ABSTRACT Polymer cathodes featuring versatile designable redox‐active motifs and structural anti‐dissolution in aqueous electrolytes have attracted interest for advancing zinc‐organic batteries. However, their implementation is hindered by insulating electronic properties and sluggish ion transport, both arising from twisted molecule chains with poor structural planarity, which limits active‐site accessibility and capacity delivery. Here we design planar macromolecular semiconductors (PMSs) by fusing a four‐electron pyrene‐4,5,9,10‐tetraone acceptor and a two‐electron tetraminobenzoquinone donator into long‐range conjugated polymeric skeletons through intermolecular π – π interactions. The highly π ‐extended planarity endows PMSs with a semiconducting property (7.64 × 10 −7 S cm −1 ) that promotes efficient electron delocalization, and yields the highest ion diffusion coefficient (6.52 × 10 −7 cm 2 s −1 ) among reported organic cathodes. Leveraging synergistic fast electron‐ion transport kinetics, the long‐range stacking of molecular planes minimizes conformational disorder, enabling near‐complete utilization (98.4%) of redox‐active quinone−phenazine motifs with an ultralow activation energy (0.19 eV). Consequently, Zn||PMSs battery liberates high capacities (442/263 mAh g −1 at 0.2/100 A g −1 ), alongside a long lifespan (60,000 cycles). Besides, PMSs cathode enables a 348 mAh zinc pouch cell with a high mass loading (20 mg cm −2 ) to operate stably for 1000 cycles. This work provides a promising direction to design planar organic semiconductors for boosting electron‐ion migration kinetics toward better zinc batteries.